CVE-2025-20340 - CVE House
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Status published High CVE-2025-20340

Cisco IOS XR Address Resolution Protocol Broadcast Storm Vulnerability

Vulnerability Description

A vulnerability in the Address Resolution Protocol (ARP) implementation of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to trigger a broadcast storm, leading to a denial of service (DoS) condition on an affected device.  This vulnerability is due to how Cisco IOS XR Software processes a high, sustained rate of ARP traffic hitting the management interface. Under certain conditions, an attacker could exploit this vulnerability by sending an excessive amount of traffic to the management interface of an affected device, overwhelming its ARP processing capabilities. A successful exploit could result in degraded device performance, loss of management connectivity, and complete unresponsiveness of the system, leading to a DoS condition.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

Cisco IOS XR Software
Vulnerable Versions:
6.5.3, 6.5.29, 6.5.1, 6.6.1, 6.5.2, 6.5.92, 6.5.15, 6.6.2, 7.0.1, 6.6.25, 6.5.26, 6.6.11, 6.5.25, 6.5.28, 6.5.93, 6.6.12, 6.5.90, 7.0.0, 7.1.1, 7.0.90, 6.6.3, 6.7.1, 7.0.2, 7.1.15, 7.2.0, 7.2.1, 7.1.2, 6.7.2, 7.0.11, 7.0.12, 7.0.14, 7.1.25, 6.6.4, 7.2.12, 7.3.1, 7.1.3, 6.7.3, 7.4.1, 7.2.2, 6.7.4, 6.5.31, 7.3.15, 7.3.16, 6.8.1, 7.4.15, 6.5.32, 7.3.2, 7.5.1, 7.4.16, 7.3.27, 7.6.1, 7.5.2, 7.8.1, 7.6.15, 7.5.12, 7.8.12, 7.3.3, 7.7.1, 6.8.2, 7.3.4, 7.4.2, 6.7.35, 6.9.1, 7.6.2, 7.5.3, 7.7.2, 6.9.2, 7.9.1, 7.10.1, 7.8.2, 7.5.4, 6.5.33, 7.8.22, 7.7.21, 7.9.2, 7.3.5, 7.5.5, 7.11.1, 7.9.21, 7.10.2, 24.1.1, 7.6.3, 7.3.6, 7.5.52, 7.11.2, 24.2.1, 24.1.2, 24.2.11, 24.3.1, 24.4.1, 24.2.2, 7.8.23, 7.11.21, 24.2.20, 24.3.2, 24.4.10, 6.5.35, 25.1.1, 24.4.2, 24.3.20, 24.4.15, 6.5.351, 24.3.30, 6.5.352, 24.4.30

Timeline

Official Publish: September 10th, 2025
Last Modified: September 10th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Weaknesses (CWE)